From c39b6f1dc2654171fb10f0217643099ecdf21939 Mon Sep 17 00:00:00 2001
From: He Sun <bochang.sh@antgroup.com>
Date: Fri, 25 Sep 2020 22:27:17 +0800
Subject: [PATCH] Eliminate compiler warnings

---
 src/libos/src/exception/mod.rs | 18 +++---------------
 src/libos/src/interrupt/mod.rs | 18 +++---------------
 src/libos/src/lib.rs           |  2 --
 src/libos/src/syscall/mod.rs   | 21 +++++++++++++++++++++
 4 files changed, 27 insertions(+), 32 deletions(-)

diff --git a/src/libos/src/exception/mod.rs b/src/libos/src/exception/mod.rs
index e14ec0f0..bb193141 100644
--- a/src/libos/src/exception/mod.rs
+++ b/src/libos/src/exception/mod.rs
@@ -5,6 +5,7 @@ use self::rdtsc::{handle_rdtsc_exception, RDTSC_OPCODE};
 use self::syscall::{handle_syscall_exception, SYSCALL_OPCODE};
 use super::*;
 use crate::signal::{FaultSignal, SigSet};
+use crate::syscall::exception_interrupt_syscall_c_abi;
 use crate::syscall::{CpuContext, FpRegs, SyscallNum};
 use aligned::{Aligned, A16};
 use core::arch::x86_64::_fxsave;
@@ -26,24 +27,11 @@ pub fn register_exception_handlers() {
 
 #[no_mangle]
 extern "C" fn handle_exception(info: *mut sgx_exception_info_t) -> i32 {
-    // Rust compiler would complain about passing to external C functions a CpuContext
-    // pointer, which includes a FpRegs pointer that is not safe to use by external
-    // modules. In our case, the FpRegs pointer will not be used actually. So the
-    // Rust warning is a false alarm. We suppress it here.
-    #[allow(improper_ctypes)]
-    extern "C" {
-        fn __occlum_syscall_c_abi(
-            num: u32,
-            info: *mut sgx_exception_info_t,
-            fpregs: *mut FpRegs,
-        ) -> u32;
-    }
-
     let mut fpregs = FpRegs::save();
     unsafe {
-        __occlum_syscall_c_abi(
+        exception_interrupt_syscall_c_abi(
             SyscallNum::HandleException as u32,
-            info,
+            info as *mut _,
             &mut fpregs as *mut FpRegs,
         )
     };
diff --git a/src/libos/src/interrupt/mod.rs b/src/libos/src/interrupt/mod.rs
index c532faef..c3b14bdf 100644
--- a/src/libos/src/interrupt/mod.rs
+++ b/src/libos/src/interrupt/mod.rs
@@ -1,6 +1,7 @@
 pub use self::sgx::sgx_interrupt_info_t;
 use crate::prelude::*;
 use crate::process::ThreadRef;
+use crate::syscall::exception_interrupt_syscall_c_abi;
 use crate::syscall::{CpuContext, FpRegs, SyscallNum};
 use aligned::{Aligned, A16};
 use core::arch::x86_64::_fxsave;
@@ -15,24 +16,11 @@ pub fn init() {
 }
 
 extern "C" fn handle_interrupt(info: *mut sgx_interrupt_info_t) -> i32 {
-    // Rust compiler would complain about passing to external C functions a CpuContext
-    // pointer, which includes a FpRegs pointer that is not safe to use by external
-    // modules. In our case, the FpRegs pointer will not be used actually. So the
-    // Rust warning is a false alarm. We suppress it here.
-    #[allow(improper_ctypes)]
-    extern "C" {
-        fn __occlum_syscall_c_abi(
-            num: u32,
-            info: *mut sgx_interrupt_info_t,
-            fpregs: *mut FpRegs,
-        ) -> u32;
-    }
-
     let mut fpregs = FpRegs::save();
     unsafe {
-        __occlum_syscall_c_abi(
+        exception_interrupt_syscall_c_abi(
             SyscallNum::HandleInterrupt as u32,
-            info,
+            info as *mut _,
             &mut fpregs as *mut FpRegs,
         )
     };
diff --git a/src/libos/src/lib.rs b/src/libos/src/lib.rs
index 1d915bac..8e98315c 100644
--- a/src/libos/src/lib.rs
+++ b/src/libos/src/lib.rs
@@ -6,8 +6,6 @@
 #![feature(allocator_api)]
 #![feature(core_intrinsics)]
 #![feature(stmt_expr_attributes)]
-#![feature(atomic_min_max)]
-#![feature(no_more_cas)]
 #![feature(alloc_layout_extra)]
 #![feature(concat_idents)]
 #![feature(trace_macros)]
diff --git a/src/libos/src/syscall/mod.rs b/src/libos/src/syscall/mod.rs
index bc8fcd95..2fbf5189 100644
--- a/src/libos/src/syscall/mod.rs
+++ b/src/libos/src/syscall/mod.rs
@@ -994,3 +994,24 @@ impl CpuContext {
         }
     }
 }
+
+// exception and interrupt syscalls share the same c abi
+//
+// num: occlum syscall number
+// info: pointer to sgx_exception_info_t or sgx_interrupt_info_t
+// fpregs: pointer to FpRegs. Rust compiler would complain about passing
+//  to external C functions a CpuContext pointer, which includes a FpRegs
+//  pointer that is not safe to use by external modules. In our case, the
+//  FpRegs pointer will not be used actually. So the Rust warning is a
+//  false alarm. We suppress it here.
+pub unsafe fn exception_interrupt_syscall_c_abi(
+    num: u32,
+    info: *mut c_void,
+    fpregs: *mut FpRegs,
+) -> u32 {
+    #[allow(improper_ctypes)]
+    extern "C" {
+        pub fn __occlum_syscall_c_abi(num: u32, info: *mut c_void, fpregs: *mut FpRegs) -> u32;
+    }
+    __occlum_syscall_c_abi(num, info, fpregs)
+}